Apparatus for recovering potassium compounds from cement-kiln gases.



H. BLUMENBERG, JR. APPARATUS FOR RECOVERING POTASSIUM COMPOUNDS FROM CEMENT KILN GASES.

1 297 639 APPLICATlON FILED MAR; 15. 1918. Patented Man 18,1919

. a 2 SHEETS-SHEET H. BLUMENBERG, JR-

-! APPARATUS FOR RECDVERING POTASSIUM COMPOUNDS FROM CEMENT KlL-N GASES. v

APPLICAUON FILED MAR 15. 1918 1297,2339. Patented Mar. 18,1919.

-2 SHEETSSHEET 2- Inven to?" w aw 4Z4 a by-product in cement kilns.

HENRY BLUMEINBERG, JR., OF 0R0 GR ANDE, CALIFORNIA.

APPARATUS FOR RECOVERINGYQPOTASSIUM COMPOUNDS FROM CEMENT-KILN GASES.

Specification of Letters Patent.

Patented Mar. 18, 1919.

Application filed March 15, 1918. Serial No. 222 765.

To all whom it may concern:

Be' it l nowftliatl3, HENiiY J r., a citizen of the United States, residing at Oro Grande, in the county of San Bernardino and State of California, have invented new and useful Improvements in Apparatus for Recovering Potassium Compounds from Cement-Kiln Gases, of which the following is a specification.

My invention relates to an apparatus-for recovering potassium salts from waste gases,

and in particular from waste gases of ce-- ment kilns. 4

The great demand forpotassium salts has started new industries for-the production of the same. One of the most successful is the production of potassium salts as In some places, the potassium salts recovered have exceeded the value of the cement and the potassium salts have become the main prod-' not. The process in brief consists in using potassium bearing minerals, such as feldand complete recovery of the potassium,

compounds carried with the cement dust in the hot gases, and the present invention relates to an apparatus which is especially adapted for recovering the potassium compounds from such gases.

In my copending application, Serial No.

214212, filed January 28, 1918, for a process of recovering potassium salts and apparatus therefor, I have disclosed and claimed an apparatus for recovering potassium compounds from the gases of a cement kiln of which the present is an improvement. The.

apparatus described in. said application recovers approximately 85% of the potassium compounds. T he present im )vements increase the efficiency of the apparatus, re-

covering practically all of it.

My invention consists n the apparatus hereinafter described and cla med.

BLUMENBERG,

In the accompanying drawings which form a part of this specification, I have illustrated an apparatus embodying my invention, and in which:

Figure 1 is a vertical Section of my apparatus.

Fig. 2 is a horizontal section taken on line 22 of Fig. 1. through the precipitating 'tower. and condenser.

Fig. 3 is a horizontal section on line 3-'3 of Fig. 1.

Fig. 4 is a diagrammatic view in plan of my apparatus, using a plurality of precipitating towers and condensers.

Referring to the drawings, 10 indicates the upper end of a rotary cement kiln which terminates in a main stack 11. A conduit 12, leads from the lower end of the stack 11 to a series of dust collecting chambers 13, 14 and 15, which may consist of any desired number. These chambers communicate with each other by means of passages 16 and 17,

formed byyertical baffle walls 18 and 19 arranged in staggered relation, as shown in Fig. 20, 21 and 22 are suitable doors in the side walls of the dust collecting chambers, whereby access may be gained thereto.

A passage way 23 leads from the last chamber 15 into the lower end of the precipitating tower 24-wliieh is shown hereas cylindrical in type, but may be of anydesired form. A series of perforated bafile' plates 25 are horizontally mounted in the tower 24. 27 is a suitable valve in conduit 12. 28 is a lid of cover for the main stack 11 whicl" is normally held closed by means of a cord 29 and Windlass 30. If for any reason the apparatus for the recovery of the potash is not to be used, the conduit 12 is closed by means of valve 27 and the cover 28 is opened, allowing the cement gases .to escape through themain stack 11.

31 is a centrifugal pump for circulating water by means of pipe 32 and'spray nozzle 33 through the precipitatin tower 24. The

liquid collected in the inc med bottom 34 I of the precipitating tower 24 is returned by means of pipe 26 to the pump 31. When the water has collected sufiicient cement dust and potash so that resulting magma or slurry is handled with difiiculty by the pump 31, the slurry is pumped into a series of evaporatin pans 35, 36 and 37 by means of a branch pipe 38 leading from pipe 32 and which is provided with a valve 39. 40 is a valve in pipe 32 which is closedwhen valve 39,}is opened to divert the slurry into said pans. .41, 42 and 43 are valved outlet pipes leading from the branch pipe 38 into evaporating pans 35, 36 and 37, respectively. Each pan is provided with a valved outlet 44 through which the slurry, after the desired degree of concentration has been reached, is-allowed to how into the dust collecting chambers 13, 14 and 15.

I The gases after passing through the precipitating tower 24 are drawn through conduit 45 by means of a'blow'er or fan 46 into the lower part of the condenser 47 where the rest of the potash and cement dust vis recovered. The condenser 47 is providedwith a central cooling portion consistin of a container 48 through which a. series 0 spaced vertical pipes 49 open at both ends are arranged. The coolin water is admitted through the valved in ets 50. 51 is a valved outlet for the heated water. The gases comp in from the precipitating, tower 24 are consi erably cooled and saturated with aqueous vapor and steam, which on passing through pipes 49 are condensed. During the condensation, the dust particles and potassium compounds, still carried by the gases after their passage through the precipitating tower 24 are collected in the bottom of the condenser 47 whence the same is run through a valved outlet pipe 52 into an evaporating pan 53 provided with a suitable steam coil 54. After the desired degree of concentration has been reached in the evaporating pan 53, the same may be led through a valved; 'pipe 55 'to the centrifugal pump 31 and as desired. The use of a iplurality of dust collecting chambers, precipitating towers and condensers will avoid ,thejshut down of the apparatus in case any due of the apparatus mentioned should require repairing or cleaning. Furthermore, a; more rapid and stack 11 is closed, the valve 27 in conduit 12 dust collecting chambers 13, 14 and 15.

efficient recovery of the potash may be effected. 0

In the operation of the apparatus, the

is opened and the gases passed through tlIIe u doing so they give off part of their heat to the pans 35, 36 and 37, concentrating the slurry therein. A part of the dust is collected in the chambers-13, 14 and 15. The gases passing through the precipitating tower come in contact with the water sprayed by nozzle 33 and approximately 85% of the menace desired consistency of the slurry is obtained, when the valve 40 is. closed and valve 39 in branch pipe 38 is opened and the slurry 'is pumped into the concentrating pans 35', 36

and 37. After further concentration, the.

slurry is allowed to flow to the bottom of the dust collecting chambers'13, 1'4 and 15 where it will come in contact with the hot d-ust collected therein and further evaporation and concentration will take place. The dried slurry as well as the dustin the chambers 13, 14 and 15 may be removed at suitable intervals through the doors 20, 21 and 22. The gases coming from the cement kiln have a temperature of about 1200 F.; the precipitating tower 24 reduces them in temperature down to 212 F., and saturates them with steam. and vapor, which passing through the vertical pipes 49 in the condenser 47 will be condensed and in their condensation collect and precipitate'the dust particles and the. potassium compounds. carried in said gases. The aqueous mixture of cement dust and potassium compounds will flow down the pipes to the bottom of the condenser whence the same may be run ofl into the evaporating pan 53 whence the same may be pumped through the pump 31150 the concentrating pans 35, 36 and 37 or used with the slurry in the circulation through the tower 24 until the desired concentration has been reached.

The slurry and cement dust collected from the dust collecting chambers 13, 14 and 15 is afterward. treated in the usual manner to extract the potash or the same may be sold as a fertilizer without any further treatment, the potassium compound calculated as K 0 ranging from four to eight per cent.

depending upon the richness of the raw materials in potassium. The fertilizer, in ad} dition to the potassium, contains more than. fifty per cent. of calcium oxid which is an other valuableingredient in a fertilizer.

, In some kilns which operate with dry raw materials, I prefer to use both precipitating towers and condensers. In cement kilns operating with. wet slurry the precipitating towers may be dispensed with and the corn denser alone be used, which is arranged immediately adjacent to the upperendof the cement kiln. The waste gases in cement kilns operating with wet slurry are of considerably lower temperatures than those of" cement kilns operating with dry materials and they contain sufiicient steam and aqueous vapor, which, on condensation in the vertical pipes 49 of the condenser, will precipitate the dust and potassium compounds.

The essentialfeature of this invention is the provision of a condenser with vertical; pipes which are self cleaning.- Condensers with horizontal pipes have been known, but

' the same soon become clogged with dust and ',/precipitated, matter that require frequent shut downs and cleanings, Which in the present apparatus require no attention whatever. "'I claim: 1 An apparatus for recovering potassium compounds from hot gases containing the samein suspension, comprising a dust pre-.

cipitating chamber, a precipitating tower, means for clrculatmg an aqueous mixture through said tower for precipitatin the cement dust and potassium compounc s, a con- 'denser connected with said tower, vertical tubes open 'at both ends arranged in said condenser, means for circulating a cooling medium about said tubes, means for collecting the aqueous mixture of cement dust and potassium compounds precipitated in said condenser, and means for concentrating said aqueous mixture.

Walls provide with connecting passages in staggered relation, a. precipitating chamber through which the gases after their passage to the dust collecting chambers are passed,

means for circulating a precipitating fluid in said precipitating chamber, a condenser communicating with said precipitatng chamber, vertical tubes. open at both ends vertically arranged in said condenser, means for circulating a cooling medium about said -tubes, and means for collecting the aqueous,

mixture of cement dust and potassium compounds'precipitated insaid condenser.

In testimony. whereof I have signed my name to this specification.

4 HENRY BLUMENBERG, JR. 

